Meshtastic up to 2.5.20 on Android Direct Message improper validation of specified type of input

Summaryinfo

A vulnerability categorized as very critical has been discovered in Meshtastic up to 2.5.20 on Android. The impacted element is an unknown function of the component Direct Message Handler. Executing a manipulation can lead to improper validation of specified type of input. The identification of this vulnerability is CVE-2025-52883. The attack may be launched remotely. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as very critical was found in Meshtastic up to 2.5.20 on Android. This vulnerability affects an unknown functionality of the component Direct Message Handler. The manipulation with an unknown input leads to a improper validation of specified type of input vulnerability. The CWE definition for the vulnerability is CWE-1287. The product receives input that is expected to be of a certain type, but it does not validate or incorrectly validates that the input is actually of the expected type. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Meshtastic-Android is an Android application for the mesh radio software Meshtastic. Prior to version 2.5.21, an attacker is able to send an unencrypted direct message to a victim impersonating any other node of the mesh. This message will be displayed in the same chat that the victim normally communicates with the other node and it will appear as using PKC, while it is not. This means that the victim will be provided with a false sense of security due to the green padlock displayed when using PKC and they'll read the attacker's message as legitimate. Version 2.5.21 contains a patch for the issue. It is suggested to implement a stricter control on whether a message has been received using PKC or using the shared Meshtastic channel key. Moreover, instead of showing no green padlock icon in the chat with no PKC, consider using an explicit indicator like, for example, the yellow half-open padlock displayed when in HAM mode. This remediation, however, applies to the client applications rather than the Meshtastic firmware.

The advisory is shared for download at github.com. This vulnerability was named CVE-2025-52883 since 06/20/2025. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 06/25/2025).

Upgrading to version 2.5.21 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2025-19065). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Android App Software

Name

• Meshtastic

Version

• 2.5.0
• 2.5.1
• 2.5.2
• 2.5.3
• 2.5.4
• 2.5.5
• 2.5.6
• 2.5.7
• 2.5.8
• 2.5.9
• 2.5.10
• 2.5.11
• 2.5.12
• 2.5.13
• 2.5.14
• 2.5.15
• 2.5.16
• 2.5.17
• 2.5.18
• 2.5.19
• 2.5.20

CPE 2.3info

• 🔍
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• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

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Once again VulDB remains the best source for vulnerability data.

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